Chiggers are common skin parasites that are present throughout the central part of the United States. The scientific name for chiggers is Trombicula
mites, and they are also known as harvest mites. These mites can infect and bite people, cats, and dogs, and cause severe itching. While they are difficult to prevent, they are relatively easy to treat.
Chiggers are usually found in the highest numbers during the spring and fall in grassy areas, particularly in chalky soils. The chigger mite is a small reddish-orange mite about the size of the head of a pin.
What is the life cycle of chiggers?
Eggs are laid in soil and around vegetation in late summer. Larvae hatch from the eggs and crawl onto a host animal (e.g.; cat, dog, human). They attach themselves, feed on fluids in the tissue for several days, and then leave the host. They then molt into a nymph stage, and then mature into adults. The life cycle is completed in 50-55 days. In northern areas, there are 1-2 generations per year, in southern areas, the mites can reproduce all year long.
What are the symptoms of chiggers?
In cats, chiggers often take up residence on the inside of the ears and can be seen with the naked eye. They are said to look like paprika. In dogs, they can be found around the legs, head, and abdomen. Chiggers may not cause any symptoms in some animals; others may scratch at the area where the chiggers are present. In people, the mite is usually not seen but the bite will produce a small welt, usually around the ankles, that itches intensely for several days.
How is an infestation with chiggers diagnosed?
The mite can be scraped from the inner surface of the cat's ear or off of the dog and can be identified under the microscope. However, because of the characteristic reddish color and location, a diagnosis can often be made just by visual inspection.
How is an infestation with chiggers treated and prevented?
The treatment is relatively simple and consists of either a couple of pyrethrin-based dips spaced a couple of weeks apart, or the application of a topical antiparasite drug like Tresaderm to the ears. The topical treatment with Tresaderm or pyrethrin-based ear treatment is often the simplest and most effective treatment in cats. Topical or injectable steroids can be administered to the animal for several days to help alleviate any itching.
Avoiding areas where chiggers are found is probably a good idea because they appear to live in the same locations year after year.
Can I get chiggers from my pet?
It is very unlikely that you would get chiggers from your pet. If you and your pet both have chiggers, you probably both walked through an area where there were numerous chiggers in the environment.
If you notice your cat scratching at his ears and see the characteristic pinpoint-sized red mites on the inner surface of the ears, it is probably chiggers. The mites can also be identified on the dog, particularly in severe infestations. If you suspect chiggers, contact your veterinarian and get the proper topical treatment.
Griffiths, H. A Handbook of Veterinary Parasitology. University of Minnesota Press. Minneapolis, MN; 1978:170-171.
Paterson, S. Skin Diseases of the Cat. Blackwell Science Ltd. Malden, MA; 2000.
Scott, D; Miller, W; Griffin, C. Muller and Kirk's Small Animal Dermatology. W.B. Saunders Co. Philadelphia, PA; 1995.